Yes, but y'all will notice that I mentioned the words "underground" and "corrosion" in my initial response. I did not suggest that aluminum was used inside the house, merely that it is an outstanding conductor, which it is.
It may help to look at the inverse property of conductance. The inverse of conductivity is resistivity, i.e. from which we derive resistance. For Cu it is on the order of 1.6 and for Al it is 2.6, corresponding to what Geary suggests (with the exception that his Cu value is inflated... conductivity for Cu should be around 60 - 61, unless he is looking at percentages as related to Cu, which could be the case).
At first glance 1.6 and 2.6 seems like a large difference. However, it is important to examine the units associated with these numbers. That would be 30 - 50 Mega Mhos (Mega Seimans) conductivity for Al and 60 - 61 Mega Mhos (Mega Seimans) for Cu, corresponding to 2.6x10E-8 ohm for Al (read as "2.6 times 10 to the minus 8"), and 1.6x10E-8 ohms for Cu (read as "1.6 times 10 to the minus 8").
How many of you have a meter that can detect the difference between 0.026 micro ohms and 0.016 micro ohms, which also can be read as 26 nano ohms and 16 nano ohms, respectively
?
So the choices for corrosion are conductive grease, as used in the power industry, or a separate grounding conductor to bypass the bracket corrosion... no big deal either way.